Conventional digital imaging devices or cameras have a lens (which may include multiple lens elements) that focuses image light onto an image sensor that measures the image light and generates an image based on the measurements. FIG. 1 illustrates a common configuration for a digital imaging device 100. FIG. 1 includes an image sensor 101 including optical efficiency lenses 110 disposed over photosensitive substrate 103. Optical efficiency lenses 110 function to draw as much light as possible into the pixels for measurement. Optical efficiency lenses 110 may be microlenses disposed over each pixel of image sensor 101. An infrared (“IR”) filter 115 may be disposed over optical efficiency lenses 110 to filter out IR light from being measured by image sensor 101. Color filters 107 may filter out certain colors of light so that each pixel only receives one color of light. For example, color filter 107 may include a Bayer pattern that allows four neighboring pixels to receive red, green, green, and blue light, respectively.
Lens 120 is disposed over image sensor 101 to focus image light 199 onto the pixels of image sensor 101. Lens 120 may include convex and/or concave lens elements 123 that give lens 120 a certain focal length or lengths. Lens 120 may include an autofocus module 127 that moves at least some lens elements 123 in the z-axis 121 in order to focus image light 199 onto image sensor 101.
Often times, digital cameras are integrated into mobile devices. Currently, a large percentage of digital cameras that are integrated into mobile devices may not have a physical shutter but instead rely on electronic shutters (e.g. global shutters or rolling shutters) to control the “exposure” of the pixels in an image sensor. Therefore, without a physical shutter shielding the image sensor, ambient light may be incident on the image sensors of digital cameras for long periods of time, which can damage the digital camera.